The present invention relates generally to self-closing water valves.
More particularly, it relates to a self-closing water valve with a valve closing member formed for example as a valve plate with a shaft and closing or releasing a valve seat.
Self-closing water valves identified also as water quantity regulators are known in the art. One of the known water valves is openable by means of an adjusting wheel by hand through an auxiliary valve. A cam disc displaces an auxiliary closing member at the water inlet against a spring force. The auxiliary closing member releases the auxiliary valve seat and thereby provides a complete hydraulic opening of the main closing member under the action of the water pressure. Water flowing through the auxiliary valve seat drives a water motor arranged in the interior of the water valve housing and subsequently flows further to a water output, especially for watering plants.
Due to the water pressure difference before and after the main closing member, it hydraulically closes automatically when the auxiliary closing member closes the auxiliary valve seat. The main closing member is formed as a waved diaphragm with a small stroke clamped in the housing and closing with its edges a throughflow region as a cover. By lifting of the diaphragm from the throughflow region the water valve is opened.
When the diaphragm material is aged or foreign particles or impurities are settled on it, the diaphragm can open not completely in some situations, so that the water valve becomes untight. Moreover, the hydraulic opening of the water valve is performed more or less slow depending on the condition of the auxiliary valve.
In a further development of the known water valve the valve closing member is formed as a plate valve with a shaft. The valve plate corresponding to the diaphragm of the first known valve is composed of a bending-resistant, wear-resistant material and is fixedly connected with the shaft. The valve plate abuts with its periphery against the valve seat and the valve housing relative to the water input. The opening of the valve is performed not hydraulically, but instead only through adjusting means which act on the shaft and is displaceable together with the valve plate. Due to bending-resistant closing member there is no the danger here of untightness since impurities can be displaced and squashed. However, during opening of the valve the valve member must be moved against the pressure of the water with significant forces over the shaft. Depending on the height of the water pressure, the forces for opening of the valve, for example with very high pressure which is available in Germany, range from unpleasant to unbearable or at least reduce the operational comfort, affect the operation and increases wear between the movement transmitting parts and the valve closing body. The service life is reduced as well.
Further water valves are known in which switching time is controlled. Since it is dependent on the exterior energy, further disturbing factors are introduced, for example, they are less robust than the conventional water valves.